Field of the Invention
The present invention relates to a liquid crystal display (LCD) device, and more particularly, to a liquid crystal material having improved reliability and response time and an LCD device including the liquid crystal material.
Discussion of the Related Art
As the society has entered in earnest upon an information age, various display devices, such as an LCD device and an organic light emitting diode (OLED) display device, for displaying images are required.
The LCD device uses optical anisotropy and polarization properties of liquid crystal molecules. The liquid crystal molecules have a definite alignment direction as a result of their thin and long shapes. The alignment direction of the liquid crystal molecules can be controlled by application of an electric field across the liquid crystal molecules. As the intensity or direction of the electric field is changed, the alignment of the liquid crystal molecules also changes. Since incident light is refracted based on the orientation of the liquid crystal molecules due to the optical anisotropy of the liquid crystal molecules, images can be displayed by controlling light transmissivity.
Since the LCD device including a thin film transistor (TFT) as a switching element, referred to as an active matrix LCD (AM-LCD) device, has excellent characteristics of high resolution and displaying moving images, the AM-LCD device has been widely used.
The LCD device includes two substrates facing each other and a liquid crystal layer therebetween. The LCD device further includes a pixel electrode and a common electrode for generating an electric field. The liquid crystal layer is driven by the electric field.
For example, the LCD device is used for repeatedly displaying similar images in a public place. It may be called to as a public display. Since the public display repeatedly displays similar images in very long times, the reliability of the LCD device is an important fact.
Namely, in the public display, the displayed images remain in the screen as an afterimages, and the image quality of the public display is degraded by the afterimages. As a result, high reliability is required in the LCD device as the public display.
However, the LCD device for the public display having high reliability has a disadvantage in a response time. The LCD device for the public display having the high response time has a disadvantage in the reliability.